Spreader Failure

[selene]

Okay, this is a weird one. Out sailing - brisk, 18kn (reefed). Nice sail for a few hours, then large bang.

Connection between spreader and mast broke. Oddly - not sure yet, mast is being pulled as we speak - the spreader on the other side seems also to be showing a crack in the same place. I was on a starboard tack, and it was the starboard spreader, so it would have been under pressure. But...

Fortunately it was the spreader that I fly my burgees on, so I was able to retrieve the spreader itself from ocean using the burgee line. And some quick maneuvering prevented more damage to the rig - as coincidence would have it, I was on my way to the yard to replace the $tanding rigging (it's been 20 years, so seems like time).

So:

- Anybody else experienced this kind of failure?

- Any idea where to get a new pair of spreader-mast connectors?

[grzano]

Hi Selene,

Sorry that happened to you and that  I do not have any information the spreader, but I would like to ask if you are willing to share, what it cost to replace the standing rigging as mine is questionable? My rig is a concern that I've been having for a while now. I have also been thinking of Dyneema, but am uncertain about the materials and stretching.

Wishing you the best.

Greg

[Dolce_Vita]

Selene,

  I'm a little puzzled by this, as it seems to imply that the spreader base was under a lot of twisting moment.  This can happen if the rig was loose enough that the downwind spreader could "flop" around, and then get bound up in the wrong position when tacking and it becomes upwind.

In a properly installed and tensioned spreader, the forces should all be straight down the length of the spreader, and it should not "flop" under any conditions.

When we purchased Dolce Vita, her rig was too loose and her downwind spreader flopped.  When rebuilding the mast, i found that the base of the spreader tubes had split where they fitted over the casting that is bolted to the mast.  That's why I'm surprised your castings broke instead!

With new standing rigging, the rule-of-thumb I found was to start with the tension around 10% of breaking strength, and adjust as needed from there. This resulted in a stiff rig that did not flop under any point of sail.

[selene]

Ed - yeah, it's a puzzler. The rig was tight, I tune it every year. I think I may have bumped it during a raft-up, which cracked the base, and then under the wind load it parted. I'm just hoping the RigRite parts will fit, otherwise I'll have to get the new bases fabricated.

Greg - I'll let you know the cost when all is done. Right now there is a ~4 week lead time on new rigging, as the weather has been mild and many people are out sailing! And the SF Bay is not a great place to benchmark prices, as EVERYTHING here seems to cost a premium over other parts of the US.

I was also very interested in Dyneema, but nobody local deals with it - there is an outfit in LA (https://www.colligomarine.com/) that specialises in Dyneema standing rigging. They recommend a product called "Dyneema Dux", apparently heat treated to reduce any initial stretching. I have to say, the product looks very good - lightweight, easy to repair, and super strong.

[grzano]

Hi Selene,

Thank you. I look forward to hearing more about your repairs.

Best regards,

Greg